Wide-field coded aperture hard X-ray telescopes enable the discovery and characterization of the most energetic and transient astrophysical phenomena in the Universe, including Gamma-ray bursts, outbursts from supermassive black holes with jets (blazars), black hole and neutron star binary mergers, and outbursts from black hole and neutron star X-ray binaries. A next-generation instrument under development is the High Resolution Energetic X-ray Imager (HREXI). HREXI is a CdZnTe (CZT) imaging hard X-ray (3-300 keV) detector designed to identify and localize transient astrophysical events. Drawing on heritage technology developed during the ProtoEXIST 1 & 2 balloon-borne X-ray telescope experiments[1]}, [2]}, [3]}, [4]}, HREXI is composed of a modular array of 256 closely tiled pixellated 19.9 \(\times \)  19.9 mm\(^{2}\) , 3 mm thick CZT detectors. Each CZT detector is bonded to an individual Application Specific Integrated Circuit (ASIC) with gold studded conductive-epoxy (Fig. REF a). Previously developed and flown on the the NuSTAR mission[5]}, the NuSTAR ASIC (NuASIC)[6]} readout enables tiling of large detector area assemblies for coded aperture imaging (Fig. REF b). While NuSTAR operates eight individual detectors (2 \(\times \)  2 for each of the two focusing telescopes), a coded aperture X-ray telescope requires orders of magnitude more detectors to achieve desired sensitivities over a larger field of view. Fabrication, testing and assembly of hundreds of CZT and NuASIC detectors will be labor intensive and every improvement to the integration process will result in large reductions to schedule time and cost. To overcome this challenge, the HREXI program plans to replace NuASIC wire bonds with Through Silicon Vias (TSVs)[7]}. In this paper, we detail efforts to streamline screening and testing of TSV NuASICs before bonding to CZT.
